反应详情

The product of Example 17, Step A, methyl 4-[[2,3-difluoro-6-[[(2-hydroxyethoxy)amino]carbonyl]phenyl]amino]benzoate (306 mg, 0.84 mmol) was dissolved in ethanol (40 mL), to which was added 1 M NaOH solution (40 mL). This mixture was stirred at room temperature for 15 hours, then poured into 1 M HCl solution (100 mL). The resulting precipitate was extracted with EtOAc (3×80 mL) and the combined EtOAc extracts then combined and washed with water (2×100 mL) and saturated NaCl (100 mL). The organic fraction was dried (Na2SO4), the solvent removed under reduced pressure and the resulting residue purified by column chromatography on flash silica (50% EtOAc/hexanes as eluant) to afford 4-[[2,3-difluoro-6-[[(2-hydroxyethoxy)amino]carbonyl]phenyl]-amino]benzoic acid as a crystalline white solid (168 mg, 57%); m.p. (EtOAc/hexanes) 180–183° C.

1. extractionThe resulting precipitate was extracted with EtOAc (3×80 mL)
2. washwashed with water (2×100 mL) and saturated NaCl (100 mL)
3. dry with materialThe organic fraction was dried (Na2SO4)
4. customthe solvent removed under reduced pressure
5. customthe resulting residue purified by column chromatography on flash silica (50% EtOAc/hexanes as eluant)